U.S. patent application number 10/279203 was filed with the patent office on 2003-04-24 for pneumatic vehicle tire.
Invention is credited to Besson, Marc-Andre, Burfien, Jorg, Gerke, Hans Werner, Hartwig, Andreas, Holste, Werner, Jeromin, Dieter, Kaldune, Norman, Rosner, Michael, Rotter, Wolfgang, Seevers, Jorn, Speckhals, Ulrich, Weber, Frank.
Application Number | 20030075255 10/279203 |
Document ID | / |
Family ID | 7703358 |
Filed Date | 2003-04-24 |
United States Patent
Application |
20030075255 |
Kind Code |
A1 |
Besson, Marc-Andre ; et
al. |
April 24, 2003 |
Pneumatic vehicle tire
Abstract
A pneumatic vehicle tire of radial construction, especially for
automobiles, is provided. The tire has a profiled tread strip, a
belt structure of at least two belt plies, bead regions having bead
cores, and a carcass having load-carrying members of steel cord. In
the tire the carcass forms a C-ply construction and contains steel
cords of three or five steel filaments, which all have the same
diameter of 0.12 to 0.1 5mm.
Inventors: |
Besson, Marc-Andre;
(Garbsen, DE) ; Burfien, Jorg; (Garbsen, DE)
; Gerke, Hans Werner; (Neustadt, DE) ; Hartwig,
Andreas; (Garbsen, DE) ; Holste, Werner;
(Hannover, DE) ; Jeromin, Dieter; (Hannover,
DE) ; Kaldune, Norman; (Charlotte, NC) ;
Rosner, Michael; (Seeize, DE) ; Rotter, Wolfgang;
(Hannover, DE) ; Seevers, Jorn; (Burgdorf, DE)
; Speckhals, Ulrich; (Hannover, DE) ; Weber,
Frank; (Neustadt, DE) |
Correspondence
Address: |
ROBERT W. BECKER & ASSOCIATES
Suite B.
707 Highway 66 East
Tijeras
NM
87059
US
|
Family ID: |
7703358 |
Appl. No.: |
10/279203 |
Filed: |
October 23, 2002 |
Current U.S.
Class: |
152/554 ;
152/451; 152/548; 152/556 |
Current CPC
Class: |
Y10T 152/10855 20150115;
B60C 9/0007 20130101; B60C 9/08 20130101; B60C 15/0045
20130101 |
Class at
Publication: |
152/554 ;
152/548; 152/556; 152/451 |
International
Class: |
B60C 009/02; B60C
015/00; B60C 009/04; B60C 009/00; D07B 001/06 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 23, 2001 |
DE |
101 52 165.0-18 |
Claims
What we claim is:
1. A pneumatic vehicle tire of radial construction, comprising: a
profiled tread strip; a belt structure having at least two belt
plies; bead regions having bead cores; and a carcass that in the
tire forms a C-ply construction, wherein said carcass is provided
with load-carrying members in the form of steel cords that each
contain three or five steel filaments, wherein said filaments all
have the same diameter of 0.12 to 0.15 mm.
2. A pneumatic vehicle tire according to claim 1, wherein said
diameter of said steel filaments is 0.13 mm.
3. A pneumatic vehicle tire according to claim 1, wherein said
steel cords have a 1.times.3 construction.
4. A pneumatic vehicle tire according to claim 3, wherein said
steel cords have a twist length between 3 and 7 mm.
5. A pneumatic vehicle tire according to claim 1, wherein said
steel cords have a 1.times.5 construction.
6. A pneumatic vehicle tire according to claim 5, wherein said
steel cords have a twist length between 4 and 8 mm.
7. A pneumatic vehicle tire according to claim 1, wherein said
steel filaments comprise a steel of the strength class SHT.
8. A pneumatic vehicle tire according to claim 1, wherein in a ply
of said carcass the number of steel cords per dm is between 90 and
160.
9. A pneumatic vehicle tire according to claim 8, wherein the
number of steel cords per dm is between 100 and 135.
10. A pneumatic vehicle tire according to claim 1, wherein regions
of a ply of said carcass are guided-back and extend to below edge
regions of a radially innermost one of said belt plies and overlap
with the latter over a range of about 10 to 30 mm.
11. A pneumatic vehicle tire according to claim 10, wherein said
overlap range is 20 to 30 mm.
12. A pneumatic vehicle tire of radial construction, comprising: a
profiled tread strip, a belt structure having at least two belt
plies, bead regions having bead cores, and an at least single-ply
carcass that is provided with load-carrying members in the form of
steel cords of 1.times.3 or 1.times.5 construction, wherein said
steel cords comprise steel filaments of the strength class SHT, and
wherein said filaments have a diameter of 0.13 mm.
13. A pneumatic vehicle tire according to claim 12, wherein in said
carcass the number of steel cords per dm is between 90 and 160.
14. A pneumatic vehicle tire according to claim 13, wherein the
number of steel cords per dm is between 100 and 135.
15. A pneumatic vehicle tire according to claim 12, wherein a ply
or plies of said carcass are looped about said bead cores and back
up.
16. A pneumatic vehicle tire according to claim 12, wherein a ply
or plies of said carcass form a C-ply construction.
17. A pneumatic vehicle tire according to claim 16, wherein
portions of a ply of said carcass are guided back to below edge
regions of a radially innermost one of said belt plies and overlap
with the latter over a range of about 10 to 30 mm.
18. A pneumatic vehicle tire according to claim 17, wherein said
overlap range is 20 to 30 mm.
19. A pneumatic vehicle tire according to claim 12, wherein said
steel cord has a 3.times.0.13 mm construction with a twist length
between 3 and 7 mm.
20. A pneumatic vehicle tire according to claim 12, wherein said
steel cord has a 5.times.0.13 mm construction with a twist length
between 4 and 8 mm.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a pneumatic vehicle tire of
radial construction, especially for automobiles, and has a profiled
tread strip, a belt structure having at least two belt plies, bead,
regions with bead cores, and a carcass having load-carrying members
of steel cord.
[0002] It has already been proposed, to dispose in the carcass ply
or plies of the radial carcass of a pneumatic vehicle tire,
load-carrying members of steel cord instead of the conventional
load-carrying members of textile material. For example, reference
is made to EP-A-0 849 098, where it is proposed to use steel cords,
the filaments of which have a diameter between 0.1 mm and 0.45 mm,
whereby the steel filaments are supposed to have a tensile strength
of -2000.times.D+4400 MPa, where D is the filament diameter. A
preferred range for the diameter of the steel filaments is between
0.14 and 0.42 mm. Pursuant to this reference, a number of different
steel cord constructions are furthermore used, starting with
constructions that have two filaments, up to constructions that
have more than ten filaments. The preferred construction is a 1+5
construction. EP-A-0 987 128 also deals with the same subject
matter, whereby here as the lower limit for the diameter of the
steel filaments of the steel cord 0.07 mm is mentioned with the
upper limit being 0.45 mm. The preferred range is between 0.07 and
0.12 mm. Here also the steel filaments can form a number of
different steel cord constructions, as already mentioned. Both
documents emphasize using a particularly high-strength steel, a
so-called UHT (ultra high tensile) steel in order to be able to
achieve a reduction in weight at high strength.
[0003] It is therefore an object of the present invention to
provide a pneumatic vehicle tire having steel cords as the
load-carrying members in the carcass, whereby the tire has a low
weight yet is significantly improved with regard to its handling
characteristics and its durability or service life.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] This object, and other objects and advantages of the present
invention, will appear more clearly from the following
specification in conjunction with the accompanying schematic
drawings, in which:
[0005] FIG. 1 is a cross-sectional view through one exemplary
embodiment of an inventive pneumatic vehicle tire, and
[0006] FIGS. 2 and 3 are cross-sectional views through exemplary
embodiments of inventive steel cords.
SUMMARY OF THE INVENTION
[0007] The pneumatic vehicle tire of the present invention is
characterized primarily in that the carcass forms a C-ply
construction in the tire, and contains steel cords of three or five
steel filaments, which for all steel filaments have the same
diameter of 0.12 to 0.1 5 mm.
[0008] It has been shown that the inventive combination of a C-ply
construction with steel cords as load-carrying members that have
three or five filaments having a diameter of 0.12 to 0.15 mm
significantly improves the handling characteristics and the
durability of the tire. A steel cord that comprises three or five
filaments, the diameter of which is in the range of between 0.12
and 0.15 mm, is optimally suited for use as a load-carrying member
in the carcass of a tire due to its strength and flexibility. Tires
embodied pursuant to the present invention demonstrate excellent
handling characteristics, for example brief response times to
steering forces, a markedly precise steering performance, a precise
action when driving in curves, and a very stable behavior in the
fringe range when driving in curves. Surprisingly, one can also
achieve a significant reduction in the wear of the tread strip with
the inventive tires in contrast to tires having a carcass with
textile load-carrying members, such as load-carrying members of
rayon. The C-ply construction contributes to an optimum
introduction into the tire of the static and dynamic forces that
occur during operation of the tire, whereby such forces can then be
carried by the tire.
[0009] Pursuant to one preferred embodiment of the invention, the
diameter of the filaments is 0.13 mm. Preferred constructions for
the steel cord are 1.times.3 or 1.times.5 constructions. The steel
used for the steel filaments is preferably a steel of the strength
class SHT (super high tensile) having a tensile strength between
3350 and 3650 MPa. These embodiments have proven in tests to be
particularly advantageous for the aforementioned tire
characteristics, and therefore represent the optimum.
[0010] The carcass ply that with the C-ply construction extends
laterally below the radially innermost belt ply of the belt
construction should overlap with this belt ply by respectively at
least 10 mm, and especially up to 30 mm.
[0011] The aforementioned object is further inventively realized
where the steel cord in the carcass has either the 1.times.3 or the
1.times.5 construction and comprises steel filaments of the
strength class SHT with a diameter of 0.1 3 mm.
[0012] It has been shown that the use of such steel cords in the
carcass or in the carcass plies of an automobile tire is optimal
with regard to strength and flexibility, whereby the flexibility is
of great significance for the durability or service life of the
tire. In this connection, a steel cord of the construction
5.times.0.13 appears even better than a steel cord of the
construction 3.times.0.13 with regard to resistance to fatigue.
Steel cords of both the 1.times.5 as well as the 1.times.3
constructions have shown themselves to be particularly advantageous
with regard to their dynamic material characteristics. Steel cords
having the same construction, but of individual filaments having a
smaller diameter, have proven to be of unsatisfactory strength,
while steel cords having steel filaments of greater diameter have
shown themselves to be too stiff.
[0013] The advantages that can be achieved are independent of the
structural design of the carcass, which can have a conventional
configuration where the ends are looped about or that has a carcass
ply that forms a C-ply construction. In this connection,
improvements of the handling characteristics that can be achieved
with inventively embodied tires are to a large extent independent
of the configuration of the carcass. Whether a configuration having
conventional looped-around ends or a C-ply construction is
selected, in each case the aforementioned improvements, such as
briefer response time to steering forces, very precise steering
performance, precise behavior when driving in curves, as well as
stable behavior in the fringe range when driving in a curve and an
exact behavior when changing loads and tracks are observed.
[0014] In addition, the number of steel cords per decimeter in the
carcass ply contributes to the optimization of the aforementioned
characteristics. The number of steel cords should be between 90 and
160 per dm, especially between 100 and 135 per dm.
[0015] Further specific features of the present invention will be
described in greater detail subsequently.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0016] Referring now to the drawings in detail, the pneumatic
vehicle tire shown in FIG. 1 is a radial automobile tire which, as
its main components, is provided with a profiled tread strip 1,
sidewalls 2, bead regions 3 having bead cores 4, a carcass 5, the
configuration of which will be described in greater detail
subsequently, a belt 6, filler or profiled core portions 7, and an
inner liner 8, which is substantially airtight. In the illustrated
embodiment, the belt 6 is comprised of two belt plies 6a, 6b, which
have a conventional configuration and can therefore comprise, in
particular, steel cords that are embedded in rubber and in each ply
extend parallel to one another. In this connection, the steel cords
within the belt ply 6a cross the steel cords that are disposed
within the second belt ply 6b. In addition, the radially inwardly
disposed belt ply 6b is wider than the upper belt ply 6a.
[0017] In the illustrated embodiment, the carcass 5 forms a
so-called C-ply construction. In this connection, during build-up
of the tire a single carcass ply 5a is applied in such a way that
in the finished tire, in the sidewalls 2 the carcass ply 5a,
accompanied by inclusion of the filler 7, extends about the bead
cores 4 from the inside to the outside and is guided back up to
beneath the belt 6 so that in the sidewalls 2 the ply 5a forms a
double-ply carcass 5. The free ends extend to below the radially
inner belt ply 6b and overlap the latter in a range of about 10 mm
to 30 mm, especially 20 to 30 mm.
[0018] Certain advantages are associated with such an embodiment of
the carcass 5. With a C-ply construction, the carcass ply 5a can be
disposed in the tire in such a way that its load-carrying members
extend in a radial direction or deviate from a precise radial
direction at an angle that is of an order of magnitude of about 3
to 4.degree.. Due to the looping-around in the bead region, and the
guidance back to the belt 6, there results in the sidewalls 2 a
crossed arrangement that is advantageous for the rigidity of the
tire, namely a crossed arrangement of the load-carrying members in
the two plies.
[0019] As a variation from the illustrated and particularly
advantageous C-ply construction, the carcass can, in a conventional
manner, also be provided with turned-up portions that end in the
sidewalls.
[0020] Pursuant to the present invention, independently of their
configuration, the carcasses 5 contain, as load-carrying members,
steel cords having a specific construction and configuration. Such
a steel cord comprises either three or five filaments that are
twisted with one another, in particular in the construction
1.times.3 or 1.times.5. FIG. 2 shows a cross-section through a
steel cord 10 of 1.times.3 construction having three filaments 12;
FIG. 3 shows a cross-section through a steel cord 11 of 1 .times.5
construction having five filaments 12. The individual filaments 12
of the steel cords 10, 11 have a diameter that is between 0.12 mm
and 0.15 mm. The preferred diameter of the filaments 12 is 0.13 mm.
In this connection, the length of twist of a steel cord of
1.times.5 construction is between 4 and 8 mm, especially 5.5 mm,
and the length of twist of a steel cord of 1.times.3 construction
is between 3 and 7 mm, especially 4.5 mm. It has been shown that
with tires, the carcass of which contains, as load-carrying
members, such steel cords of 1.times.3 or 1.times.5 construction,
which in addition belong to the strength class SHT, significant
improvements of some tire characteristics can be achieved,
especially with regard to the handling characteristics.
[0021] It is particularly advantageous if the number of steel cords
10, 11 in the carcass ply 5a are between 90 and 160 filaments/dm,
especially between 100 and 135 filaments/dm.
[0022] It is also advantageous that tires having the inventively
configured carcass have a lower weight than do tires having
conventional carcasses with textile load-carrying members. Tires
embodied pursuant to the present invention are furthermore
characterized relative to conventional tires by an improvement of
the so-called flat-spot property, whereby flat-spot denotes
deformation of a resting tire that previously ran hot during
operation. Furthermore, there surprisingly results a clear
improvement in the operation of the tread strip and a reduction of
non-uniform wear.
[0023] The steel filaments 12 of the steel cords 10, 11, as
previously mentioned, preferably comprise steel of the strength
class SHT (Super High Tensile), but it is also possible to use
steel of the strength class UHT (Ultra High Tensile). Steel
filaments of the strength class SHT have a tensile strength between
3350 and 3650 MPa, while steel filaments of the strength UHT have a
tensile strength of greater than 3650 MPa.
[0024] The specification incorporates by reference the disclosure
of German priority document 101 52 165.0-16 of Oct. 23, 2001.
[0025] The present invention is, of course, in no way restricted to
the specific disclosure of the specification and drawings, but also
encompasses any modifications within the scope of the appended
claims.
* * * * *